Water resistant and impermeable carpet underlays provide a way to clean spills on carpet more thoroughly by containing the spill above the padding, thus preventing the spill from wetting the padding and flooring underneath. The resistant or impermeable barrier provides advantages since, if a spill is not removed from under the carpet, the spill will allow the growth of mold, mildew, and bacteria. Such underlays may be treated with antibacterial and antifungal agents. Not only may the padding and wood flooring deteriorate as a result, but such conditions are conducive to the formation of odors and allergens.
Spills on fitted or wall-to-wall carpeting are particularly insidious since detection and prevention of the seepage into the padding following a spill is typically impractical with large or fitted carpets. A spill on broadloom carpeting often puddles on the padding or flooring where it can not be removed by cleaning.
This spill then accelerates the growth of mold, mildew and odors. By allowing spills to be more thoroughly cleaned, a water resistant or impermeable backing reduces the growth of mold and mildews which cause odors.
Murphy, in U.S. Pat. Nos. 5,601,910 and 5,763,040, described processes to treat a carpet underlay to make it substantially impermeable to spills. By careful selection of both the water repellent finish and adhesive, the water impermeable underlay was adhered to the underside of the carpet creating a barrier to spills.
Underlays are usually attached to the underside of the carpet by an adhesive applied to the upper side of the underlay. Alternatively the underlay may be treated with adhesive on both sides to attach it to both the underside of the carpet and the padding. The adhesive prevents movement of the underlay as the carpet is laid, and also prevents any movement due to traffic after the installation is complete. Such application methods have been highly effective, but there are added costs associated with the adhesive, necessary release papers, and installation.
The prior art also describes water impermeable carpeting constructed using impermeable backings such as those based on poly(vinyl chloride) and polyurethane to replace the usual latex backing, and also sheets of plastic, such as polyethylene and poly(ethylene/vinyl acetate), that are laminated to the carpet.
However, such backings are expensive, create manufacturing difficulties, and prevent desirable breathability (air permeability) of the carpet.
It would be advantageous if a simpler method for laying the padding, underlay, and carpet were available which would reduce the costs associated with the adhesive, necessary release papers, and installation. The present invention provides such an improved process for installation of a water resistant or water impermeable underlay with padding and carpet.